Applicants claim the benefit as a National stage entry of a PCT application pursuant to 35 U.S.C. xc2xa7371 of International Application No. PCT/DE00/03289 filed Sep. 21, 2000, published in the German language, which in turn claims priority in its parent case, German Application No. 199 50 253.6 filed Oct. 18, 1999.
1. Field of the Invention
The invention relates to a tube mat made of elastomer material in the form of an extruded product, comprising at least
a first face side and a second face side, which are arranged perpendicular or at an angle in relation to the direction of extrusion, as well as
a plurality of tubes extending between the two face sides parallel with the direction of extrusion.
2. The Prior Art
A tube mat of the type specified above is described, for example in the published documents DE-C-33 45 388; DE-C-34 03 234; DE-C-35 24 719; and EP-B-0 569 867.
In conjunction with the tube mats known until now, it was possible for dirt and water to penetrate the tube mat on the face sides, which then frequently led to the fact that the tube mat was no longer capable of fully satisfying its function with respect to its elasticity.
Now, the problem of the invention is to provide a tube mat in connection with which the penetration of dirt and water is excluded to the greatest possible extent, combined with an improvement of the elastic properties of the article and, at the same time, a longer useful life, all this under permanent dynamic stress.
Said problem is solved in that at least a part of the tubes are closed at adjustable intervals, specifically with formation of an enclosed air column in each case, whereby the closure of the tube forms a one-piece elastomer composite with the tube mat.
The closure of the tube may extend in this connection in one line perpendicular or at an angle unequal to 90xc2x0 in relation to the direction of extrusion, preferably at an angle of from 45xc2x0 to 80xc2x0.
Particularly the following two variations are employed with respect to the tube closure:
The first and the second face sides of the tube mat are closed, specifically with formation of a completely sealed tube system.
The first and/or the second face side(s) are/is partially or completely open, specifically with formation of a correspondingly open face zone. However, a sealed tube system is present in the center zone of the tube mat.
The following materials are usefully employed for the tube mat:
The tube mat consists of a vulcanized rubber mixture based on ethylene-propylene-diene copolymer (EPDC), whereby the hardness in Shore A amounts to 30xc2x0 to 50xc2x0.
The alternative material is a vulcanized rubber mixture based on natural rubber (NR), whereby the hardness in Shore A amounts to 30xc2x0 to 60xc2x0 in the present case.
Additional mixing ingredients usually contained in the rubber mixture are, for example sulphur or sulphur donors, accelerators, zinc oxide, fillers and anti-aging agents.
The tube mat as defined by the invention is applied particularly in the field of rail traffic technology, specifically within the framework of vibration and sound damping in the following areas of application:
The tube mat serves as an elastic mat in the railroad bed or ballast. Under this aspect, the tube mat is referred also as a railroad bed mat or below-ballast mat. The mat may be covered in this connection by a protective layer of fleece or the like, if need be.
The tube mat has the function of an elastic insert in crosstie systems.
Furthermore, the tube mat serves as an elastic substrate in rail support sites, in particular again in the form of a rail substrate that is arranged underneath the foot of the rail.
Furthermore, the problem of the invention is to provide for the tube mat of the type described above a method that assures a safe closure of the tubes, and which is economical.
A particularly advantageous method for producing the tube mat as defined by the invention is characterized by the following steps of the method:
Following extrusion, the tubes are pressed shut with the help of a pressure applicator roller that is provided with pins which are distributed over the circumference of the roller, specifically with the formation of beads or closing bridges; and
vulcanization is carried out subsequently.